function [t,y]=euler(a,b,h,y0)
%function [t,y]=euler(a,b,h,y0)
%Solution using Euler's Method.  Determines a solution y(t)
%  for t=a to t=b using step size h and initial condition y0.
%  To change the differential equation, go to the second to
%  last line- In the command window, type:  edit euler.m

t=a:h:b;
n=length(t);
y=zeros(n,1);
y(1)=y0;

for i=2:n
    y(i)=y(i-1)+h*f(t(i-1),y(i-1));
end

%*********************************
function dy=f(t,y)
dy=1-t+4*y;
return